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.TH AIO_CANCEL 3C "Feb 5, 2008"
.SH NAME
aio_cancel \- cancel asynchronous I/O request
.SH SYNOPSIS
.LP
.nf
#include <aio.h>

\fBint\fR \fBaio_cancel\fR(\fBint\fR \fIfildes\fR, \fBstruct aiocb *\fR\fIaiocbp\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBaio_cancel()\fR function attempts to cancel one or more asynchronous I/O
requests currently outstanding against file descriptor \fIfildes\fR. The
\fIaiocbp\fR argument points to the asynchronous I/O control block for a
particular request to be canceled. If \fIaiocbp\fR is \fINULL\fR, then all
outstanding cancelable asynchronous I/O requests against \fIfildes\fR are
canceled.
.sp
.LP
Normal asynchronous notification occurs for asynchronous I/O operations that
are successfully canceled. If there are requests that cannot be canceled, then
the normal asynchronous completion process takes place for those requests when
they are completed.
.sp
.LP
For requested operations that are successfully canceled, the associated error
status is set to \fBECANCELED\fR and the return status is \fB\(mi1\fR\&. For
requested operations that are not successfully canceled, the \fIaiocbp\fR is
not modified by \fBaio_cancel()\fR.
.sp
.LP
If \fIaiocbp\fR is not \fINULL\fR, then if \fIfildes\fR does not have the same
value as the file descriptor with which the asynchronous operation was
initiated, unspecified results occur.
.SH RETURN VALUES
.sp
.LP
The \fBaio_cancel()\fR function returns the value \fBAIO_CANCELED\fR to the
calling process if the requested operation(s) were canceled. The value
\fBAIO_NOTCANCELED\fR is returned if at least one of the requested operation(s)
cannot be canceled because it is in progress. In this case, the state of the
other operations, if any, referenced in the call to \fBaio_cancel()\fR is not
indicated by the return value of \fBaio_cancel()\fR. The application may
determine the state of affairs for these operations by using
\fBaio_error\fR(3C). The value \fBAIO_ALLDONE\fR is returned if all of the
operations have already completed. Otherwise, the function returns \fB\(mi1\fR
and sets \fBerrno\fR to indicate the error.
.SH ERRORS
.sp
.LP
The \fBaio_cancel()\fR function will fail if:
.sp
.ne 2
.na
\fB\fBEBADF\fR\fR
.ad
.RS 10n
The \fIfildes\fR argument is not a valid file descriptor.
.RE

.sp
.ne 2
.na
\fB\fBENOSYS\fR\fR
.ad
.RS 10n
The \fBaio_cancel()\fR function is not supported.
.RE

.SH USAGE
.sp
.LP
The \fBaio_cancel()\fR function has a transitional interface for 64-bit file
offsets.  See \fBlf64\fR(7).
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Committed
_
MT-Level	MT-Safe
_
Standard	See \fBstandards\fR(7).
.TE

.SH SEE ALSO
.sp
.LP
.BR aio_read (3C),
.BR aio_return (3C),
.BR aio.h (3HEAD),
.BR signal.h (3HEAD),
.BR attributes (7),
.BR lf64 (7),
.BR standards (7)
.SH NOTES
.sp
.LP
Solaris 2.6 was the first release to support the Asynchronous Input and Output
option. Prior to this release, this function always returned \fB\(mi1\fR and
set \fBerrno\fR to \fBENOSYS\fR.
